942 Evidence for Great Holocene Earthquakes Along the Outer Coast of Washington State: B. F. ATWATER 944 Interferon-y and B Cell Stimulatory Factor-1 Reciprocally Regulate Ig Isotype Production: C. M. SNAPPER AND W. E. PAUL 947 Electrophoretic Evidence for Genetic Diploidy in the Bracken Fern (Pteridium aquilinum): P. G. WOLF, C. H. HAUFLER, E. SHEFFIELD 949 Effect of Lizards on Spider Populati...

Schistosomes, unlike malaria parasites, are in their diploid stage when targeted by the human immune system. Diploids can be either homozygous or heterozygous. The difference has profound significance for developing immunity and yet has not previously been addressed. We examined the implications of zygosity on immunity to a diploid pathogen, Schistosoma japonicum and showed that the diploid sta...

Previously, we reported that chromosomes contain a giant filamentous protein, which we identified as titin, a component of muscle sarcomeres. Here, we report the sequence of the entire titin gene in Drosophila melanogaster, D-Titin , and show that it encodes a two-megadalton protein with significant colinear homology to the NH 2 -terminal half of vertebrate titin. Mutations in D-Titin cause chr...

Based on the genetic analysis of Trypanosoma cruz¡ zymograms (Tibayrenc et al., 1981a, 1981b) we proposed the hypothesis of diploidy for this parasite. Lanar et a/. (1981) arrived at the same conclusion by a study of Trypanosoma cruz¡ DNA. Nevertheless, our observations were principally based on one of the main Bolivian isoenzymic strains, which showed numerous heterozygous loci (strain 2). The...

The enzyme profiles of 109 Bolivian stocks of Trypanosoma cruzi were determined by cellulose acetate electrophoresis using the four enzymes: malate dehydrogenase (oxaloacetate decarboxylating) (NADP+) (E.C.1.1.1.40, ME), phosphogluconate dehydrogenase (E.C.1.1.1.44, 6PGDH), phosphoglucomutase (E.C.2.7.5.1, PGM) and glucosephosphate isomerase (E.C.5.3.1.9, GPI). As previously, two principal zymo...

Previously, we reported that chromosomes contain a giant filamentous protein, which we identified as titin, a component of muscle sarcomeres. Here, we report the sequence of the entire titin gene in Drosophila melanogaster, D-Titin, and show that it encodes a two-megadalton protein with significant colinear homology to the NH(2)-terminal half of vertebrate titin. Mutations in D-Titin cause chro...

We have identified, cloned and sequenced the three ribosomal RNA (rRNA) operons (rrn) present in the facultative photoheterotroph Rhodobacter sphaeroides. DNA sequence analysis has identified the 16S, 23S, and 5S rRNAs, two tRNAs (ile and ala) in the spacer region between the 16S and 23S rRNAs, and an f-met tRNA immediately following the 5S rRNA gene of all three operons. Physical mapping, gene...